Carrier Aggregation Channel Sounding for 5G

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Solution Overview

Problem

Traditional cellular wireless communications networks face challenges in characterizing wireless channels, particularly in millimeter wave spectrum, which is crucial for 5G deployments, as they lack efficient methods for measuring channel properties like complex impulse response, path loss, and angle of arrival across broad frequency bands.

Innovation Solution

The method employs carrier aggregation in existing 5G network infrastructure, where base stations transmit wideband channel sounding waveforms, and receivers process these using multiple carriers to generate combined frequency domain sample sets, aligning them in gain and phase to measure channel properties without the need for a dedicated transmitter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional cellular wireless communication methods are used, then existing network infrastructure can be maintained, but channel characterization in millimeter wave spectrum is insufficient

Engineering Contradiction:

Improvechannel characterization accuracyVSAvoidfrequency band coverage

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The wideband channel sounding waveform is divided into multiple component carriers that can be processed separately and then combined. Each carrier is processed through discrete Fourier transform to generate frequency domain sample sets, which are then aligned and combined to achieve comprehensive wideband channel characterization.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Existing 5G network infrastructure is made multi-functional by enabling base stations to transmit both data traffic and channel sounding waveforms using the same hardware. The receiver can process both regular communication signals and channel sounding signals, achieving dual functionality without additional dedicated transmitters.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If wideband channel sounding is implemented, then comprehensive channel characterization is achieved, but system complexity increases

Engineering Contradiction:

Improvechannel property measurement accuracyVSAvoidsignal processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The complex wideband channel sounding process is segmented into manageable steps: receiving multiple component carriers, performing discrete Fourier transform on each carrier separately to generate frequency domain sample sets, aligning the sample sets in gain and phase, and finally combining them. This segmentation reduces processing complexity compared to handling the entire wideband signal at once.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system processes channel sounding on a per-carrier basis rather than requiring full wideband processing at once. By generating and combining frequency domain sample sets from multiple carriers incrementally, the processing load is distributed and managed more efficiently.

Inventive Principle:

Principle #16Partial or excessive action

3Adaptability or versatility

If carrier aggregation is used for channel sounding, then broad frequency band coverage is achieved, but processing multiple carriers increases computational load

Engineering Contradiction:

Improvefrequency band coverageVSAvoidprocessing energy consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The channel sounding process is divided into independent per-carrier processing stages. Each carrier is transformed to frequency domain separately using discrete Fourier transform, allowing for efficient parallel or sequential processing that reduces overall computational energy compared to processing the entire aggregated bandwidth as a single wideband signal.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of processing all carriers simultaneously at full bandwidth, the system processes each carrier individually and combines the results. This partial processing approach at each stage reduces the instantaneous computational energy requirement while achieving the same overall channel characterization across the aggregated frequency band.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11228381B2Channel sounding using carrier aggregation

Publication Date: 2022.01.18 AT&T INTELLECTUAL PROPERTY I L P

AI summary

An example method may include a processing system of a channel sounding receiver having a processor receiving from a base station, at a location, a channel sounding waveform via a plurality of carriers, sampling the channel sounding waveform via the plurality of carriers to generate a plurality of per-carrier time domain sample sets, and processing the plurality of per-carrier time domain sample sets via a plurality of discrete Fourier transform modules to provide a plurality of per-carrier frequency domain sample sets. The method may further include the processing system aligning the plurality of per-carrier frequency domain sample sets in gain and phase to provide a combined frequency domain sample set and measuring a channel property at the location based upon the combined frequency domain sample set.